A parameter which is very important in weaving and which essentially determines profitability is the performance of a machine, a machine group or an entire weaving mill. The machine manufacturers have always made efforts to increase the performance, but these have hitherto, in practice, been restricted only to the avoidance, reliable detection and rapid elimination of machine stoppages. Only very recently has it been acknowledged that the article change and warp change have a relatively high potential for rationalization which can be utilized to increase the performance. Two directions of endeavored are appropriate for this, on the one hand substantial automation and on the other hand such a high degree of simplification that these operations can be carried out by a single person.
The present invention comes within the latter sector and relates to a method and an apparatus for the simplified warp change on weaving machines, on which the end portion of a warp is pulled forwards over a specific length, in which method the warp yarns of the woven-out warp are fixed and cut off by a rail-like member and the warp yarns of the new warp are clamped on a tie-in frame which has clamping members and which is transported to the weaving machine, on which the warp-yarn layer of the woven-out warp is inserted into the clamping members.
These operations are known and have been practiced for a long time, for example in the tying of warps by means of the tying-in machine USTER TOPMATIC (USTER being a registered trademark of Zellweger Uster AG), but this concerns the traditional warp change which is not automated and which, in practice, is usually carried out by several persons. With regard to an automation of the warp change, two proposals have recently been made, these having so-called one-sided clamping rails (Swiss Patent Applications No. 1193/91 and 2741/91) which can be inserted behind the warp-yarn regulator after the old warp has been pulled forwards. After the warp yarns have been clamped, they are cut off just behind the one-sided clamping rail and the clamping rail is then pulled back towards the tying-in frame. This operation requires a driving and control mechanism which involves a relatively high outlay and which is itself relatively expensive.